Rock (Likely Sedimentary)

Fossilized Brachiopod

Brachiopoda (likely Order Spiriferida or Productida)

Sulfide Ore (likely Galena and Sphalerite in Quartz)

Lead-Zinc Ore (PbS and ZnS)

Granite pebble

Granite; chiefly quartz, potassium feldspar, plagioclase, and minor biotite/hornblende

Polished banded agate (likely chalcedony)

Microcrystalline quartz/chalcedony, SiO₂, with possible iron-oxide inclusions

Sandstone (Banded Sandstone)

Clastic Sedimentary Rock (primarily SiO2 with iron oxide impurities)

Quartzite (or Iron-Stained Quartz Pebble)

Silicon Dioxide (SiO2) with Ferric Oxide inclusions

Jasper Breccia

Silicon Dioxide (SiO2) with impurities

River Rocks (Basalt and Sedimentary Stones)

Mafic Igneous Rock (Basalt) and Clastic Sedimentary Rock

Chert (or potentially Jasper/Chalcedony)

SiO2 (Silicon Dioxide)

Potassium Feldspar (Orthoclase)

Orthoclase (KAlSi3O8)

Ironstone Concretion (Ironstone Gourd)

Limonite/Goethite Concretion (FeOO(H))

Weathered granitic gneiss (probable)

Quartz–feldspar–biotite gneiss; compositionally similar to granite

Rounded basalt cobble

Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase and pyroxene, commonly with minor olivine and iron oxides

Sand Tiger Shark Tooth Fossil

Carcharias taurus (fossilized tooth)

Blue Onyx (Dyed Agate)

Cryptocrystalline Quartz (SiO2) with artificial pigment

Petrified Wood

Silicified Wood (primarily SiO2)

Sandstone

Sandstone (composed predominantly of Quartz, SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Sandstone with Manganese Staining

Quartz Arenite / Sedimentary Rock

Sandstone (Quartzose)

Arenite (primarily SiO2)

Sandstone

Arenite (SiO2 based)

Sandstone

Arenite (primarily SiO2)

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Polished/tumbled calcite

Calcite (calcium carbonate, CaCO₃)

Mixed polished river stones

Likely quartz, quartzite, chert/jasper, and possibly limestone or marble

Quartz (Milky/Clear variety)

Silicon Dioxide (SiO2)

Quartz (Milky/Cloudy Variety)

Silicon Dioxide (SiO2)

Botryoidal Black Chalcedony Geode (Black Grape Agate)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Sandstone (Micaceous)

Arenite (composed primarily of SiO2)

Sea Shell (Mollusk Shell)

Calcium Carbonate (Aragonite/Calcite)

Jasper

Microcrystalline Quartz (SiO2)

Purple Chalcedony

Silicon Dioxide (SiO2)

Fossil Bivalve Shell

Class Bivalvia (e.g., Veneriidae family)

Pyrite in Matrix

Iron Disulfide (FeS2)

Smoky quartz-bearing pegmatitic rock

Quartz, SiO₂, likely with feldspar and mica inclusions

Ferruginous Sandstone (River Pebble)

Clastic Sedimentary Rock (Iron-rich)

Tumbled quartz (likely clear quartz)

Quartz, silicon dioxide (SiO₂)

Rounded granitic cobble

Granite or granitic gneiss; primarily quartz, feldspar, and mica

Weathered rhyolite or felsic volcanic rock

Rhyolite, commonly quartz–alkali feldspar–plagioclase with iron-oxide alteration

Tumbled black-and-white stone, likely dendritic agate or jasper

Cryptocrystalline quartz (SiO₂), possibly chalcedony with manganese-oxide dendrites

Granite (Weathered)

Phaneritic Plutonic Rock (primarily Quartz, Feldspar, and Mica)

Granite (specifically Pink Granite)

Phaneritic Plutonic Rock (High Potassium Feldspar Granite)